Blade lashing



-D. c. DAVIS BLADE LASHING Feb. 22 1927.

Filed July 24, 1925 INVENTOR Patented Feb. 22, 1927.

UNITED STATES: PATEN T' OFFICE.

DAVID C. DAVIS, OF CHESTER, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELEC-TRIC &, MANUFACTURING COMPANY, A CO'RPORATIQN OF PENNSYLVANIA.

BLADE LASHING.

Application filed July 24,1925. Serial No. 45,789.

lashing for the blades, efiective to minimize vibration thereof.

In the accompanying-drawings, forming a part of this specification, Fig.1' is a fragmentary sectional View showing a turbine blade carryingelement having a segment of turbine blades mounted thereon with myimimproved lashing means applied thereto Fig. 2 is'a sectional view, inplan, of two blades shown in Fig. 1; Fig. 3 is a cross-sectional view ofthe lashing of Fig. 1 Fig. 4 is a longi-- tudinal sectionalview of twoblades showing a modified form of my invention; Fig. 5 is a view similarto Fig. 4 showing a further modification of my invention; and Figs. 6,7- and 8 illustrate still further modifications.

Turbine blade lashing as heretofore known to me has usually consisted ofa wire or similar means inserted through a series of aligned holes in arow of turbine blades and joined to theblades either by distortion ofthe metal in thelashing wire-or by fusion of metal such as by solderingor brazing the;

lashing wire to the blade or both. Difiicul' ties have been encounteredwith both of these means. In cases where the lashing wire is'distortedbetween the blades in or. der to form engagement therewith, ithas been found that after a comparatively short period of service, thewires have become 7 V loosened in the holes, leaving the blades free tovibrate. Where the lashing wire'is sol dered or brazed to the, blade, ithas been found that theheat incident to soldering or brazing sometimeshas a deleterious effectupon the physical; properties of the blades.

In accordance with my invention I have overcome .the aforementioneddifliculties by providing individual lashingmembers which 7 are securedto each of the blades and to'each other. threaded engagement'with ablade. In the manufacture of the blades, holes are pro videdthereinwhi'ch mayor maynot be threaded for the reception of theindividual lashing members. Where the holes in the blades are notthreaded, individual lashing members may conveniently be formed in themanner described in the patent tocI-Iey'man My invention relates toelastic fluid tur- Preferably each of the members is in;v

Rosenberg, No. 1,482,151 issued January 29, 1924, and the individuallashing members driven through the holes in, theblades. Lashing membersformed in this manner and 'driven into the holes in the blades form a.tight engagement with the blades by reason of distortion of metal in theblades. Preferably, the members are made long enough so that theyoverlap between adjacent blades and abut" adjacent blades in a row. Uponassembly the overlapping members maybe joined together by fusion ofmetal such as soldering, brazingor welding, at a point remote from theblade structure and .thus have no deleterious effect upon the physicalproperties of the blade.

Referring now to "the drawing, I show in Fig. 1 at 10 a fragment of a trrbine blade carrying element, for example,a turbine rotor, having asegment of blades 1111 mounted thereon.' Each of the blades 11 isprovided with a hole '12 for the insertion of a lashing member. Inaccordancewith this modification the .holes 12 are left unthread-e'd andindividual lashing members 13 are provided with steep pitchedlongitudinally extending threads 14 and are driven into the holes 12,.forming a tight engagement with the blades by reason of distortion ofthe metal of the blade. As'shown in Fig.2 the members 13 are madeofsufiicient length 'tooverlap between adjacent bladesandto abut thefront and back respectively of adjacent blades 11 in a segment ofblades. When assembled as shown in Fig. 2, the overlapping members form,ontheir upper sides, a convenient trough for' soldering or brazing themtogether, Fig. 3 clearly showinghow the solturbine blade lashing is tominimize vibration. of the blades which it does by raising i the naturalperiod of vibration of the blades.

:The greater the stiffness of the lashing between adjacent blades in arow, the 'great- -er resistance to vibration is effected, and thenatural period of vibrationof the. blades is raisedto a greater degree;It will begapparentfrom Fig. 2 that lashingso applied is extremely.rigid between theblades in a row with verylittle expense of material ofthe blade itself. Thus the maximum of resistance to vibration isafforded by this. form offlashing. FWhile I havefshown; all'the' bladessimilar, each being, provided with a slightly skewed hole, I may, ifdesired, employ blades having alternate holes slightly otlset, so thateach pin lies entirely within a plane normal to the turbine axis. Such astructure is shown in Fig. 6 to be described later.

In accordz'ince with the modification shown in Fig. 4, I show lashingmembers 16-16 havinii longitudinally extending steep aitched threads 17thereon similar to the menibers 13 shown in land 2. In accordance withthis modification, however, the inenibers 16 do not overlap betweenadjacent blades but are arranged so that their ends abut as at 18between adjacent blades.

Upon assembly. the abutting ends oi. the

members 16 may be joined together by adjacent blades as i '7 M i to terma strong lashing structure.

electrio welding: and thus term a sturdy unitary structure. Preferablyalternate members have right-hand threads and the remainder left-handthreads so that the tendency to unscrew is neutralized.

In Fig. h I show the blades 11 as being provided with threaded holes21-21 and having inserted therein individual lash ingr n'ieinbers22-5lt2, said members 22 being provided with crmventional threads 23-1.?In the manntacture of blades the members 22 are screwed into the blades11 sr rthat upon inbly they abut. between t 24.. The abutting membersmay then be joined to other by fusion of metal, preferably electricwelding, as shown and described for Fig. 4. Right and left hand threadsnniyalsobe used to advantage to prevent unscrewing of the assernbledstructure.

Under certain comlitions, I ma tightly drive smooth taper pins 26-f2binto holes inthe blades shown in Fig. (i.tl1ese pins overlapping as inthe structure oi Figs. 2 and 3 and being subsequently joined The pinsare not showed in the blades but .al ternate holes inthe bladesareottset.

Referring to Figs. 7 and 8, 1 may form the lashing members with some h.outer ends 30 and 31 and provide ifllfii'lp pl .flied threads along arelatively short enlarged. body portiohtlfi which is driven into a blade33 engaging therewith by distortion of the [hotel of the blade. Withthis form oi. lashing" the ends aie preferably joined togetherintermediateblades in a row as show-n in Figs. and 5.

From the foregoing it will. be apparent that I have dev sed an improvedlashing eneans for turbine blades wherein the lashing;

member is in tight engagement with the blade and oined to other lashingmembers I ata point remote from the blade structure between adjacentblades.

ll hile I .fhaveshown my invention several forms, 1t will be obvious tothose skilled together intermediate the blades 5 in the art that it isnot so limited. but is susceptible of various other changes andmodifications. without i'leparting {P0111 the spirit thereof. and Idesire. therefore. that onlysuch limitations shall. be placed thereuponas are imposed by the prior art or as are specihcall set forth in theappended claims.

What I claim is:

1. A. lashing; means tor turbine blades coinpnising, cooperatinglashingmembers in threadedengagement with a. 'acent blades and joinedtogether interlnediiite the blades by "fusion of metal.

In a turbine, a row oi' blades having holes provided therein for the i1.ertion of lashing members, and lashing members in the holes in threadedengagement with the blades and joined together intermediate the bladesby :tushion of metal.

21. In a turbine, a. row oi blades having holes provided therein for theinsertion of lashing members. lashing members comprising pin-like bodieshaving high pitched threads extending longitudinally of the bodiesdriven into theholes mi engaging with the blades by reason ofdeformation oil? material and joined together iriterinediate adjacentblades by fusion of metal.

x4. bashing. means for a row of turbine blades comprising individuallashing members applied to each blade of a segment of blades saidlashing inembers overlapping between blades and abutting adj aeentblades.

:3. Lashing means for a row of turbine blades comprising individuallashing incinbers applied to each bl ade of a segment of blades, saidlashing members"overlapping between lllades and abutting adjacentblades, and being joined togetl'ier l'lQbWGGn blades by fusion oi metal.

ti. Lasl'iing means "for a row of turbine blades comprisingindiiidnallashing 1ne1nhers having: high pitched threads driven through holes inthe bladesand engaging lherewiil'i by reason of deformation of ma terialsaid lashing .n'iembers overlajiiping between adjacent blades and beingijoiined together by f'ushionol' liietal. I i

i. Lashingmeans for a row o l turbine blades comprising individuallashing-members having high pitched threadsextending longitudinallytlieiieoidriven through holes T t-ho il l and gagging the-rewi th byreason ot de urination of inaterial, said lashingancmbers overlai rpi ngear-l1 other and abutting adjacent blades and being joined 1y tushion ofmetal. i j

lashing structure for turbine blades embodying an elongatedbodypenetrating and lightly engaging each blade, respjew tivel a11dprojecting from each time thereo'l, said bodies being so disposedthatthe portions projecting from two immediately adjacent blades lie in sideby side relation, and means for joining said portions.

9. A lashing structure for turbine blades embodying an elongated bodypenetrating and tightly engaging each blade, respectively, andprojecting from each face thereof, said bodies being so disposed thatthe portions projecting from two immediately adsubscribed my name this14th day of July DAVID C. DAVIS

